drm/i915: Retire the VMA's fence tracker before unbinding

drm/i915: Retire the VMA's fence tracker before unbinding

Since we may track unfenced access (GPU access to the vma that
explicitly requires no fence), vma->last_fence may be set without any
attached fence (vma->fence) and so will not be flushed when we call
i915_vma_put_fence(). Since we stopped doing a full retire of the
activity trackers for unbind, we need to explicitly retire each tracker.

Fixes: b0decaf75bd9 ("drm/i915: Track active vma requests")
Signed-off-by: Chris Wilson <[email protected]>
Cc: Joonas Lahtinen <[email protected]>
Cc: Tvrtko Ursulin <[email protected]>
Link: http://patchwork.freedesktop.org/patch/msgid/[email protected]
Reviewed-by: Tvrtko Ursulin <[email protected]>